The proliferation of data transport networks, most notably the Internet, is causing a revolution in telephony and other forms of real-time communication. Businesses that have been accustomed to having telephony traffic and data traffic separately supported over different systems and networks are now moving towards so-called “converged networks.” In these networks, telephone voice traffic and other forms of real-time media are converted into digital form and carried by a packet data network along with other forms of data. Now that the technologies are feasible to support converged networks, voice over data transport offers many advantages in terms of reduced capital and operating costs, resource efficiency and flexibility.
To meet the demand for voice over data transport, service providers and network equipment vendors are faced with the challenges of establishing new protocols and standards, recognizing new business models, implementing new services, and designing new equipment in a way that would have been difficult to imagine twenty years ago. For example, a new generation of end user terminal devices are now replacing the traditional telephones and even the more recent PBX phone sets. These new sets, such as those offered by Cisco Systems Inc. and Pingtel Corporation, may connect directly to a common packet data network, via an Ethernet connection for example, and may feature large visual displays to enhance the richness of the user interface.
Even before such devices were developed, computers equipped with audio adapters and connected to the Internet have been able to conduct some rudimentary form of Internet telephony, although the quality was unpredictable and often very poor. The emphasis now is upon adapting Internet Protocol (IP) networks and other packet transport networks to provide reliable toll-quality connections, easy call set-up and enhanced features to supply full-featured telephony as well as other forms of media transport. Some other types of media sessions enabled by such techniques may include video, high quality audio, multi-party conferencing, messaging and collaborative applications.
Of course, as a business or residential communications subscriber begins using such voice-over-packet communications to replace conventional telephony, there will naturally be an expectation that the quality of the connections and the variety of services will be at least as good as in the former telephone network. People have grown accustomed to having a telephone connection available whenever it is necessary. This is especially true in the case of emergencies where having an available telephone line can be most critical.